GraphViz 一个用于Swift软件包。 要求 迅捷5.2+ GraphViz （仅用于渲染） 用法 import GraphViz import DOT var graph = Graph ( directed : true ) let a = Node ( " a " ), b = Node ( " b " ), c = Node ( " c " ) graph. append ( Edge ( from : a, to : b)) graph. append ( Edge ( fro